Basement construction in Hampstead.
Kensington · W8 · Kensington new-build housesCompleted work, photograph
Basements under Hampstead houses, designed to Camden’s rules from the first drawing. Engineered, monitored and built by one team.
A Hampstead basement starts with the ground.
- Policy A5
- One storey, under half of each garden
- Burland 1
- The most damage a neighbour may suffer
- 7 days
- A budget estimate, typically
NU Projects is a design and build company in Fulham SW6, founded in 2010. We handle basement conversion and construction in Hampstead NW3, under one contract. A basement runs £450 to £780 a sq ft, construction only. Call 020 7731 6841, and a budget estimate typically follows within seven days.
Hampstead sits on a hill, with springs and clay beneath it.
Camden asks for a Basement Impact Assessment before it decides.
It covers groundwater, drainage, flooding and the structure next door.
An independent auditor checks it, at the applicant’s cost.
We commission that work first, then design the basement around it.
What the council allows in Hampstead.
- Council
- London Borough of Camden, under its Local Plan adopted in July 2017.
- One storey
- Policy A5. One storey only, and never under an existing basement.
- The garden
- No more than half of each garden. Less than 1.5 times the house’s footprint.
- Impact
- A Basement Impact Assessment, independently audited. Neighbour damage is capped at Burland category 1.
- Hampstead plan
- The Hampstead Neighbourhood Plan, adopted July 2025, adds tests on groundwater and trees.
- Coming next
- Camden’s draft 2026 plan renames the policy D6. It keeps one storey and half the garden.
Source: Camden Local Plan 2017, Camden’s Basements guidance 2021, and the Hampstead plan 2025. Read on 5 October 2026. Policies change, so we read them again for your address.
Built below ground across London.
Kensington·New build
Kensington new-build houses
Three floors below ground, in Kensington W8. Engineered and built by our team.
See the project
Chelsea·Townhouse
Chelsea basement and extension
A new basement and a kitchen extension, in Chelsea.
See the projectCompleted work, photographs
What basement conversion costs in Hampstead.
£450 to £780a sq ft, construction only. Our basement band.
£180k to £300kConverting an existing basement. A project total, from our 2026 cost guide.
£500k to £900k+Digging a new basement. A project total, from our 2026 cost guide.
Hampstead ground often adds engineering and monitoring time.
The band is per square foot, construction only. The guide figures are project totals.
Fees, the audit, party wall costs, contingency and VAT sit outside both.
Open the calculatorThe 2026 cost guideBasement costs in full
What Hampstead owners ask about basements.
In Hampstead
Basements nearby
- Basement conversion across London
- Basement conversion in Fulham
- Basement conversion in Chelsea
- Basement conversion in Kensington
- Basement conversion in St John’s Wood
- Basement conversion in South Kensington
- Basement conversion in Knightsbridge
- Basement conversion in Belgravia
- Basement conversion in Holland Park
- Basement conversion in Notting Hill
- Islington, Highgate and Primrose Hill
- Marylebone, Bayswater and Maida Vale
- Kensington
Further reading, from the journal
How deep can a Hampstead basement go?
One storey, under Camden’s Policy A5.
Camden’s draft plan describes a storey as roughly three to four metres.
It may not go beneath an existing basement.
What is a Basement Impact Assessment?
A study of groundwater, drainage, flooding and structural stability.
Camden has it independently audited, and the applicant pays.
Damage to neighbours must not exceed Burland category 1.
Does the Hampstead Neighbourhood Plan change the basement rules?
It adds to them. Policy BA1 was adopted in July 2025.
Ground movement and groundwater are assessed together with nearby basements.
Trees must be protected during construction.
How much of my Hampstead garden can a basement take?
No more than half of each garden.
It must be less than one and a half times the house’s footprint.
Beyond the house, it is set back from the neighbours.
Is Camden about to change its basement policy?
A new Local Plan is at examination, with basements as Policy D6.
The draft keeps one storey and half the garden.
We design to the plan in force, and watch the new one.
Tell us about your home in Hampstead.
Your name and one way to reply are enough. It goes straight to the studio.
- Already have an architect or designer? We build to their design. Working with your designer
- An NDA on request, and your home is never published without your consent. How we work in confidence